JES2 : Datasets are pre-step allocated

Select-mf · New User Joined: 11 May 2007 Posts: 42 Location: bangalore

I have a problem in JES2 saying datasets are pre-step allocated.

In general, my job has 5 steps. The 4th step is using one program which creates an output file using 2 input files. Now my question is the output dataset will be created after the execution of the 4th step or before the execution of the 4th step.

If the output file is created after the execution of the 4th step then what is this JES2 is saying?

Bill Dennis · Posted: Thu Jul 10, 2008 9:04 pm

Before the step executes:
1. Units allocated for tape and disk files
2. DASD datasets created (space allocated, etc.)

At step end:
1. Final disposition of files (delete, catalog, etc)

enrico-sorichetti · Posted: Thu Jul 10, 2008 9:42 pm

Select-mf · New User Joined: 11 May 2007 Posts: 42 Location: bangalore

Hi,

So you are saying the dataset is allocated before the execution of the step but it will be catalouged only after the execution of the same step, right?

Is the dataset allocated and dataset catalouged have the same meaning? I am a bit confused between dataset being allocated and catalouged, Can any one explain what is difference between the two?

Thanks.

Robert Sample · Posted: Thu Jul 10, 2008 11:14 pm

A dataset is allocated (on disk, at least) when space is defined for the dataset on a particular pack. Cataloging the dataset means an entry is placed in a system catalog allowing the dataset to be referenced without needing the volume serial and unit information (i.e., by just the DSNAME).

Select-mf · New User Joined: 11 May 2007 Posts: 42 Location: bangalore

Thanks for the information provided.

dick scherrer · Posted: Thu Jul 10, 2008 11:47 pm

Hello,